Chester County will play Surbuban One American/Continental in the other semifinal, at 9:30 a.m. Sunday.
The championship game is scheduled for 10 a.m. Monday, also in Citizens Bank.
"We wanted to get back to the 'Bank,' ' Perro said of Burlington County, which advanced to the championship game last season, losing to Lehigh Valley by a 5-3 score.
Mackie retired Delaware County's first eight hitters. He allowed one hit and faced just 10 batters.
"I was so nervous," Mackie said. "It was my first time pitching in this tournament. But once I got the first batter out, I calmed down a lot."
It was a good day for Holy Cross players. Mackie's pitching was backed by the hitting of Lancers seniors John Adryan and Chris Burns, who were a combined 4 for 5 with six RBIs.
"Those early runs really made me relax," Mackie said of Burlington County's 5-0 lead.
Adryan, an Ohio University-bound third baseman, was 2 for 3 with a pair of doubles and four RBIs. In two games in this tournament, Adryan is 4 for 6 with two doubles, a triple, a home run, and nine RBIs.
Cherokee senior Jordan Glover scored three runs from the leadoff spot and Shawnee junior Brian Lawler and Burlington City senior Anthony Coniglio had RBI hits for Burlington County, which is one victory from making its fourth appearance in the final since 2006.
"These kids play a lot of baseball," said Burlington County manager Gary Herron, the coach at Riverside. "There's not the 'awe' factor with a lot of these guys."
Pitching and defense were the most notable things about Burlington County's play.
Mackie, Perro, New Egypt junior Mike DeAnni, and Moorestown senior Dan Schurer combined to allow just eight hits, all singles, with two walks and one hit batter.
"Throw strikes and keep the ball down," Perro said of an approach that all of Burlington County's pitchers seem to take.
Burlington County backed its pitchers with near-flawless defense and turned three double plays.
The first began with a running catch in deep left-center by Moorestown senior Chance Embler, who nearly collided with Glover.
"I wasn't even sure who caught it," Herron said.
Embler fired to Cherokee senior shortstop Shane Garrett, who relayed to Coniglio at second for a 7-6-4 double play to end a Delaware County threat in the fourth.
Burlington City junior shortstop Pedro Perez and Florence senior second baseman Heath Fillmyer combined to turn 6-4-3 double plays in the sixth and ninth innings.
"Those were huge," Perro said. "When you have an infield like that, you just want to let them hit it."
Burlington County 104210000 - 8101
Delaware County 000100000 - 181
WP: Jon Mackie. LP: Dalton Mayberry. 2B: BC-John Adryan, 2, Brian Lawler, Dave Viselli.
Chester County 9, SOL National/Bicentennial 8
SOL American/Continental 2, Tri-Cape 1
Lehigh Valley 5, Inter-Ac/Independents, 3
Burlington County 8, Delaware County 1
At Citizens Bank Park.
SOL American/Continental at Chester County, 9:30 a.m.
Burlington County at Lehigh Valley, 1 p.m.
10 a.m. at Citizens Bank Park.
Contact Phil Anastasia
at 856-779-3223, email@example.com, or @PhilAnastasia on Twitter. Read his blog, "Jersey Side Sports," at www.philly.com/jerseysidesports